Push button type circuit protector

ABSTRACT

A small size circuit protector of push button type in which an electromagnetic device is disposed in the upper part of an insulation base, an insulative housing comprising built-in push buttons for said electromagnetic device, a contact mechanism, and a drive mechanism for driving said contact mechanism is disposed above said electromagnetic device, said insulative housing and electromagnetic device are covered with a case having an opening in its lower part, and said case is mounted on said insulation base.

United States Patentv Yoshino [54] PUSH BUTTON TYPE CIRCUIT PROTECTOR [72] Inventor: Akira Yoshino, Owari-Asahi, Japan [73] Assignee: Matsushita Electric Works, Ltd.,

' Osaka, Japan [22] Filed: April 13, 1971 [21] Appl. No.: 133,523

[30] Foreign Application Priority Data April 27, 1970 Japan, ..45/36134 April 27, 1970 1 Japan ..45/36135 April 27, 1970 Japan ..45/36136 s2 U.S.Cl .335/202, 335/186 511 Int.Cl. ..H01h13/04 [58] Field of Search..335/202, 186, 173; 200/169 PB [56] References Cited UNITED STATES PATENTS 3,526,863 9/1970 Vogelsang ..335/202 1,281,208 10/1918 Richetelle ..335/ 186 3,359,397 12/1967 Clark ..200/l69 PB Primary Examiner-Harold Broome AttorneyWolfe, Hubbard, Leydig, Voit & Osann [57] ABSTRACT A small size circuit protector of push button type in which an electromagnetic device is disposed in the upper part of an insulation base, an insulative housing comprising built-in push buttons for said electromagnetic device, a contact mechanism, and' a drive mechanism for driving said contact mechanism is disposed above said electromagnetic device, said insulative housing and electromagnetic device are covered with a case having an opening in its lower part, and said case is mounted on said insulation base.

9 Claims, 14 Drawing Patented Aug. 29, 197 2 5 Sheets-Sheet 1 I INVENTOR Amen YOSH/IYO BY 6 ATRNEYS I Patented Aug. 29, 1972 v 5 Sheets-Sheet 2 'INIVENTOR w I 5 H s R w w A m k A Way Patented Aug. 29, 1972 3,688,234

5 Sheets-Sheet 5 g g i INVENTOR 4 AK/m Yosnuva Patented Aug. 29, 1972 5 Sheets-Sheet 4.

' I Q lNVENT OR 'Ak/RA YOSHINO TTORNEYS Patented Aug. 29, 1972 Y 3,688,234

5 Sheets-Sheet 5 INVENTOR Ak/RA Yasnuvo ATTORNEYS PUSH BUTTON TYPE CIRCUIT PROTECTOR This invention relates to small size circuit protectors of push button type for protecting electric circuit elements such as solenoid and semiconductor elements.

The conventional small size circuit protector is such that a toggle mechanism having a control lever is disposed in the center part of the protector structure, an electromagnetic device is located on one side of the toggle mechanism, and a movable contact and fixed contact assembly is installed on the other side of the toggle mechanism. The circuit protector, therefore, is inevitably large in size in the breadth direction and requires a relatively large installation are when, for example, such circuit protector is mounted on the switchboard.

In view of the foregoing, a principal aim of this invention is to solve said problems in the prior art. Briefly, the circuit protector of this invention comprises an electromagnetic device disposed in the upper part of an insulation base, and an insulative housing which selfcontaining a push button assembly, a contact mechanism and a contact drive mechanism, said insulative housing being disposed above the electromagnetic device.

With the above aim in view, it is an object of this invention to provide a small size circuit protector installable on a reduced area in the switchboard or the like.

Another object of this invention is to provide a small size circuit protector in which a control push button, a

reset push button, a link mechanism, a release mechanism, a contact control assembly and an armature hinge assembly are set up on one base, thus forming the protector into one block whereby the production process is simplified and the overall device size is reduced.

' Another object of this invention is to provide a small size circuit protector whose operating status can be checked from outside the case.

Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.

FIG. 1 is a perspective view showing a small size circuit protector embodying this invention,

FIG. 2 is a perspective view showing the circuit protector of this invention with the parts all disassembled,

FIGS. 3A and 3B show assembly steps and FIG. 3C is a partly sectioned side view of the circuit protector when assembled,

FIG. 4 illustrates operations of the device of this invention,

FIG. 5 illustrates operations thereof, and

FIG. 6A is an enlarged fragmentary view showing the armature part and FIG. 6B is a sectional view showing the armature structure with a part cut out.

Referring to FIG. 1, there is shown a circuit protector of this invention wherein 1 is a push button, 47 is a testing lever, 70 is an upper cover, 74 is a peep opening, 60 and 24b are terminals, 65 is an insulative base, and 67 and 67' are mounting legs.

FIG. 2 shows an exploded view of the device wherein l is a push button, which is provided with a reverse U- shaped frame 2 in the lower part of the body of said button, and a lateral slit 3 in said frame 2. 4 is a link having two mutually parallel legs which are connected to each other integrally by means of an integr coupling member 5. Holes 6 and 7 are provided in the upper and lower parts of said legs, respectively. 8 is a turning plate having in its central side parts legs 9 which are bent downward. A hole 10 is made in each leg 9 of said turning plate. 11 and 12 represent shafts. The shaft 11 is inserted into the holes 6 of the link 4 which is interposed between the lateral slit 3 of the push button 1 and the frame 2, and the shaft 12 is inserted into the holes 7 of the link 4 and into the holes 10 of the turning plate 8 inserted into the lower part of the link 4 (FIG. 4).

13 is a two-split type housing block made of an insulative material and comprising a block 13a on its left side and a block 13b on its right side. These blocks 13a and 13b are symmetrical with each other. 14 is a space in which the push button 1 is interposed. An L-shaped groove 15 is provided on the side wall which forming said space 14. An arcuate groove 17 is provided on the side wall of the housing at the side of a space 16. 18 is a vertical groove along which the movable contact piece slides, and 19 is a cylindricalgroove into which the testing lever is inserted. 20 indicates a pair of lugs vertically, parallelly provided on the outer side wall of the respective housing blocks 13a and 13b. 21, 22 and 23 are lateral holes. 24a and 24b are fixed contact pieces. A contact 24a is secured to the block 13a with a pin 55 by caulking, and 24b is fixed in the hole 23' of the block 13b with a pin 55 by caulking. 25 shows a fixed contact, 26 is a slidable member, 27 is a leg provided below the slidable member 26, 28 is a spring, 29 is a movable contact piece, 30 is a movable contact, and 31 is a split ring. The leg 27 of the slidable member 26 extends through the spring 28, center hole 75 of the movable contact piece, and further through the split ring 31. This split ring is secured at the point slightly above the bottom of the leg 27. 32 is a spring supported between a supporting plate 33 engaged with a step 76 provided in the lower part of the housing block 13, and the lower part of the leg 27 of slidable member 26. 34 is a hook comprising mutually parallel arms-35a and 35b and an upper lateral bar 36. Holes 37 are provided substantially in the center of the arms35a and 35b, respectively, in alignment with each other. 38 is an armature comprising a U-shaped main body part 39, a leg 40 extended downward from the center of main body 39, arms 41a and 41b extended upward from the both ends of main body 39, and an extended end 41c of the arm 41b. Holes 42 are made through the arms 41a and 41b so as to be in alignment with each other, and a lug 43 is provided at the top of the leg 40. 44 is the heat of said lug 43. 45 is a shaft, 46 is a spring, and 47 is a testing lever. A spring 49 is set in the lower part of a leg 48 of the testing lever 47. 50 is a stopper inserted into a hole 51 of the testing lever 47. 52 is a shaft, 53 is a spring, 54 is a split ring, and 55 and 56 are pins.

57 represents an electromagnetic device, in which 58 is a core, 59 is a yoke, and 60 is a terminal. These components are assembled integral on a frame 61 made of an insulative material. 62 is a coil. A bent-over part 63 is provided at the top of the respective lateral edges of the yoke 59, and holes 63 are made in each of said bent-over parts 63. 64 is a spring.

65 shows a base made of an insulative material, on which a hollow space 66 is provided. The lower part of the electromagnetic device 57 is inserted in the space. 67 is a mounting leg of the base 65, through which a hole 68 is made. 69 represents holes for mounting a covering case.

70 is the covering case made of an insulative material. Legs 71 are provided in the lower part of the case 70, and openings 72, 73 and 74 are provided in the top wall of the case 70.

The device of this invention is assembled in the following manner. The upper part of the link 4 is installed inside the frame 2 of push button 1, the shaft 11 is inserted through the holes 3 of the push button 1 and the holes 6 of the link 4, and the both extended ends of the shaft 11 are coupled with the L-shaped grooves disposed on the housing block 13, respectively. The turning plate 8 is interposed between the legs 4 of the link 4, the shaft 12 is inserted into the holes 7 of the link 4 and through the holes 10 of the turning plate 8, and the both extended ends of the shaft 12 are coupled with the arcuate grooves 17 disposed inside the housing blocks 13a and 13b. Thus a contact drive mechanism is constituted. The leg 27 of the slidable member 26 carrying therearound the spring 28 passed through the hole 75 provided in the center part of the movable contact piece 29, the latter of which is then held with the split ring 31 to the leg 27 slidably. The both end portions of the movable contact piece are vertically slidably inserted in the vertical grooves 18 of the housing blocks 13a and 13b. The supporting plate 33 is secured to thelower part of the housing blocks 13a and 13b. The spring 32 is interposed between the supporting plate 33 and the lower surface of the movable contact piece 29 around extended lower part of the leg 27 ,so as to push the movable contact piece 29 upward.

These components form a contact mechanism.

The hook 34 is disposed inside the housing blocks 13a and 13! the arms 41a and 41b of the armature 38 are disposed outside the housing blocks 13a and 13b, and the shaft 45 extends through the hole 42 of the arm 41b of the armature 35, and also through the hole 21 of the housing block 13b, the hole 37 of the arm 35b, the spring 46, the hoes 37 of the arm 35a, the hole 42 of the arm 41a of the armature 38, and then through the hole 21 of the housing block 13a. The lower end of the link 34 is always brought into contact with the inside surface of the armature 38 as urged by the spring 46 (See FIG. 6). The testing lever 47 is inserted into the space 19 of the housing blocks 13a and 13b. The pin 50 prevents this lever 47 from being slipped out of the housing block. The spring 53 is set on each end of the shaft 11 projected outside the housing blocks 13a and 13b. The both extending ends of the spring 53 are engaged on each of the pair of lugs disposed at the respective outside wall of the housing blocks 13a and 13b. The fixed contact pieces 24a and 24b are secured to the housing blocks 13a and 13b with pins 55. These contact pieces are located so as to correspond to the movable contact pieces. Thus an operation part of the device is formed. The bent-over part 63 of the yoke 59 of electromagnetic device 57 are coupled with the lower ends of the housing blocks 13a and 13b. The pins 56 are inserted into the holes 63' of the bent-over part 63 of yoke 59 and into the holes 22 of the housing blocks 13a and 13b. Each end of the pins 56 extended out of the block 13a or 13b is made flat, thereby connecting the electromagnetic device integral with the housing blocks 13a and 13b. The case 65 is coupled with the lower end of the electromagnetic device 57, the cover is mounted on the base over the outside structure of the housing blocks 13a and 13b, the legs 71 are inserted into the holes 69 of the case 65, and the ends of the legs 71 are fused to the case so as to be integral.

FIGS. 3A and 3B show assembly status of the above described device, and FIG. 3C is an elevation showing the thus assembled device with the cover and base partly cut out.

The device of this invention is operated in the following manner. FIG. 4A shows the ON state where the fixed contacts 25 are in contact with the movable contacts 30, FIG. 4B shows the state where the device is operated at an excess current, and FIG. 4C shows the OFF state where the contacts 25 are disconnected from the contacts 30.

The OFF state is manually turned into the ON state in the following manner. Referring to FIG. 4C, when the push button 1 is depressed, the pin 11 which is extended through the lateral holes 3 of the push bottom 1 are lowered along the L-shaped groove 15, the pin 12 extended through the link 4 and turning plate 8 is lowered along the arcuate groove 17, the turning plate 8 is swung counterclockwise with its right end 8a as a fulcrum since the end 8c is in contact with the hook 34, so as to push the slidable member 26, and thus the movable contact piece 29 is lowered against resilient force of the spring 32, the contacts 30 are brought into contact with the fixed contacts 25. At this time, the pin 11 in its lowermost position is urged into the rightward corner part of the L-shaped groove 15 and is locked therein and, thereby, the contacts 25 and 30 are held in the ON state. Namely, the state as shown in FIG. 4A is established.

In the state shown in FIG. 4A, next, when an excess current flows through the coil, and the core 58 attracts the lower part of the armature 38, the armature is rotated clockwise (in the direction of arrow in FIG. 4A) about the shaft 45 as a fulcrum. As a result, the lower end of the hook 34 is pushed clockwise (in the arrow direction), the upper arm part 36 of the hook 34 is disconnected from the end 8a of the turning plate 8, and the turning plate 8 is unlocked. Due to this, the slidable member 26 is pushed upward by the upward resilient force of the spring 32, the contacts 25 are thus disconnected from the contact 30, thereby the OFF state shown in FIG. 4C is established. Note that when the testing lever 47 is manually depressed, the lower end of the leg 48 of the testing lever 47 pushes the head 44 of the armature 38 so as to rotate the latter in such manner as the armature is attracted by the core. Thus, it is possible to cause the OFF-state to occur manually operating the lever 47 in the same manner as the tuming operation due to an excess current.

The push button 1, when depressed, normally pushes the turning plate 8, but the push button 1 is free of the turning plate at the time when an excess current occurs. However, since the end of the spring 53 is engaged to the lugs 20 located outside the housing blocks 13a and 13b (See FIG. 3) and, accordingly, the push button 1 is normally pushed upward by the resiliency of the spring 53, so that the button 1 is returned to its upper position even when the plate 8 is turned clockwise so as not to transmit the upward force of spring 32.

If the spring 53 is engaged below the lugs as shown with dotted line in FIG. SC, on the other hand, the push button 1 will be always pulled downward in the direction T. Therefore, if an excess current flows through the circuit and the turning plate 8 turns out and the OFF state is established, the push button 1 is not pushed upward due to the downward force of spring 53. This function is advantageous when, for example, it is desired to allow only a specific operator to In the foregoing embodiment, the mounting arms 67 and 67' of the base 65 are on the same diagonal line. Similarly, the terminal 60 and the other terminal of the fixed contact piece 24b are on the other diagonal line as seen in FIG. 1B. Thus, the mounting arm 67 and terminal 60 are not superposed on each other, and the mounting arm 67 and the terminal of fixed contact piece 24b are also not superposed on each other. Hence the terminal 60 or that of the fixed contact pieces 2411 will not become hindered when the device of this invention is installed on a board or other machine structure.

Further, with the provision of the opening 74 in the case 70 at the position above the slidable member 26, of which the top part is colored, the ON/OFF state of the contact can be observed through the aperture 74. That is, the top part of the slidable member 26 is covered with the lift end 8b of the turning plate 8 in the state of FIG. 4A (ON state), or it is partially uncovered in the state of FIG. 4C (OFF state).

What is claimed is:

1. A push button type small size circuit protector comprising a box-shaped base made of an insulative material, at least one pair of electrical contacts for opening and closing an electrical circuit, an electromagnetic device installed on said base for controlling movement of said contacts to open said circuit, said electromagnetic device including a magnetizable core and a yoke having a top portion extending parallel to said core, the side edges of the top portion of said yoke being bent upwardly and also extending parallel to said core, a housing block split vertically into two parts and fixed above the top portion of said yoke of said electromagnetic device, a case for enclosing said side walls of the two parts of said housing block, the lower ends of the two parts of said housing block being fitted between the upwardly bent side edges on the top portion of said yoke to hold the two parts together, said case fitting down over said'housing block and fixed at its lower end to said box-shaped base with the inner surfaces of said case holding said housing block down against the top portion of said yoke and holding the'two parts of said housing block together, thereby holding together the push-button and drive mechanism housed in said block.

2. A push button type small size circuit protector according to claim 1, in which each of the two parts of said housing block is provided in its upper part with an opening for sliding said push button and a vertical groove for sliding movable contact pieces, and in its inside an lfshaped groove, an arcuate groove and holes into which a shaft is inserted, and the space formed inside said two parts when assembled is adapted to contain a vertically slidable push button, a link mechanism disposed in the lower part of said push button, a turning plate interlocked with said link mechanism, a contact mechanism operated by one end of said turning plate, and a lock mechanism engaged with the other end of said turning plate and disengaged therefrom by the movement of the armature whereby assembly of said protector is simplified by housing the majority of components within said split housing block.

3. A push button type small size circuit protector according to claim' 2, in which a reverse U-shaped frame is disposed below said push button, the upper part of the link is connected through a shaft to lateral openings disposed in said frame, and the turning plate is pivoted to the lower part of said link whereby the space in the range of the operational stroke of said push button is efiecfively utilized.

4. A push button type small size circuit protector according to claim 1, in which said base is provided with mounting legs for mounting the protector, said mounting legs being located on a diagonal line extending across the base, and terminals connected to said electrical contacts are disposed on the base and located on the other diagonal line so that said mounting legs are unobstructed by said terminals.

5. A push button type small size circuit protector according to claim-1, in which said case forms at a position above a slidable member in said contact drive mechanism an aperture for monitoring the ON/OFF state of the electrical contacts.

6. A push button type small size circuit protector according to claim 2, in which both ends of said shaft for coupling said push button and said link are projected outside said two-split housing block, a coil spring having outward extended ends is coiled on each of said projected parts of the shaft, and both extended ends of said spring are engaged with a pair of lateral projections disposed outside said housing block at both sides of said L-shaped groove so that said coil spring is set at a position to facilitate its mounting and removal to adapt the protector for return and nonreturn operation.

7. A push button type small size circuit protector according to claim 1, in which the insulative housing block encloses therein the push button at the top and said contact drive mechanism in the middle and said case is opened at its lower part and has in its upper part apertures to minimize the size of the protector.

8. A push button type small size circuit protector ac- Y cording to claim 2, in which said housing block includes a first vertical space along one side for housing the contact drive mechanism, a second vertical space along the other side for housing in its uppermost part a reset push button, in the middle part a release mechanism and in the lowermost part a hinge of the armature, and a third vertical space located in the center thereof for housing in its uppermost part said push button, in its middle part said link mechanism and in its lowermost part a connecting part of said electromagnetic device, and the shape of the horizontal cross section of said housing block substantially coincides with that of the electromagnetic device to minimize the size of the protector.

9. A push button type small size circuit protector according to claim 6, in which said pair of lateral projections extends vertically in a length substantially corresponding to that of said L-shaped grooves, so that when both extended ends of the spring mounted on each end of the shaft coupling the push button and link are engaged with the upper ends of said projections to the push button is urged upward so as to render the protector resettable, and when said both ends are with the lower ends of said projections the push button is urged downward so as to render the protector nonresettable whereby the protector can be readily adapted for return or non-return operation by varying the manner of engagement of the spring. 

1. A push button type small size circuit protector comprising a box-shaped base made of an insulative material, at least one pair of electrical contacts for opening and closing an electrical circuit, an electromagnetic device installed on said base for controlling movement of said contacts to open said circuit, said electromagnetic device including a magnetizable core and a yoke having a top portion extending parallel to said core, the side edges of the top portion of said yoke being bent upwardly and also extending parallel to said core, a housing block split vertically into two parts and fixed above the top portion of said yoke of said electromagnetic device, a case for enclosing said electromagnetic device and said housing block, a push button slidably disposed in the upper part of said housing block, a contact drive mechanism including a plurality of pivoting members operated by said push button for opening said contacts said push button and drive mechanism being housed in said two-part split housing block with all the pivoting members in said drive mechanism being supported on the opposed inner side walls of the two parts of said housing block, the lower ends of the two parts of said housing block being fitted between the upwardly bent side edges on the top portion of said yoke to hold the two parts together, said case fitting down over said housing block and fixed at its lower end to said box-shaped base with the inner surfaces of said case holding said housing block down against the top portion of said yoke and holding the two parts of said housing block together, thereby holding together the push-button and drive mechanism housed in said block.
 2. A push button type small size circuit protector according to claim 1, in which each of the two parts of said housing block is provided in its upper part with an opening for sliding said push button and a vertical groove for sliding movable contact pieces, and in its inside an L-shaped groove, an arcuate groove and holes into which a shaft is inserted, and the space formed inside said two parts when assembled is adapted to contain a vertically slidable push button, a link mechanism disposed in the lower part of said push button, a turning plate interlocked with said link mechanism, a contact mechanism operated by one end of said turning plate, and a lock mechanism engaged with the other end of said turning plate and disengaged therefrom by the movement of the armature whereby assembly of said protector is simplified by housing the majority of components within said split housing block.
 3. A push button type small size circuit protector according to claim 2, in which a reverse U-shaped frame is disposed below said push button, the upper part of the link is connected through a shaft to lateral openings disposed in said frame, and the turning plate is pivoted to the lower part of said link whereby the space in the range of the operational stroke of said push button is effectively utilized.
 4. A push button type small size circuit protector according to claim 1, in which said base is provided with mounting legs for mounting the protector, said mounting legs being located on a diagonal line extending across the base, and terminals connected to said electrical contacts are disposed on the base and located on the other diagonal line so that said mounting legs are unobstructed by said terminals.
 5. A push button type small size circuit protector according to claim 1, in which said case forms at a position above a slidable member in said contact drive mechanism an aperture for monitoring the ON/OFF state of the electrical contacts.
 6. A push button type small size circuit protector according to claim 2, in which both ends of said shaft for coupling said push button and said link are projected outside said two-split housing block, a coil spring having outward extended ends is coiled on each of said projected parts of the shaft, and both extended ends of said spring are engaged with a pair of lateral projections disposed outside said housing block at both sides of said L-shaped groove so that said coil spring is set at a position to facilitate its mounting and removal to adapt the protector for return and nonreturn operation.
 7. A push button type small size circuit protector according to claim 1, in which the insulative housing block encloses therein the push button at the top and said contact drive mechanism in the middle and said case is opened at its lower part and has in its upper part apertures to minimize the size of the protector.
 8. A push button type small size circuit protector according to claim 2, in which said housing block includes a first vertical space along one side for housing the contact drive mechanism, a second vertical space along the other side for housing in its uppermost part a reset push button, in the middle part a release mechanism and in the lowermost part a hinge of the armature, and a third vertical space located in the center thereof for housing in its uppermost part said push button, in its middle part said link mechanism and in its lowermost part a connecting part of said electromagnetic device, and the shape of the horizontal cross section of said housing block substantially coincides with that of the electromagnetic device to minimize the size of the protector.
 9. A push button type small size circuit protector according to claim 6, in which said pair of lateral projections extends vertically in a length substantially corresponding to that of said L-shaped grooves, so that when both extended ends of the spring mounted on each end of the shaft coupling the push button and link are engaged with the upper ends of said projections the push button is urged upward so as to render the protector resettable, and when said both ends are with the lower ends of said projections the push button is urged downward so as to render the protector non-resettable whereby the protector can be readily adapted for return or non-return operation by varying the manner of engagement of the spring. 